This invention relates to a lip seal assembly for establishing a sealed relationship between two spaced relatively movable members, for example (1) a housing member and a rotatable or sliding shaft member, (2) a central shaft member and a surrounding inner cylindrical surface formed in another member and (3) a pair of spaced plate members.
One object of the invention is to provide a lip seal assembly for use between two relatively movable spaced members wherein an annular lip seal element of resilient material is held in sealed relation with one of the members by means of an O-ring of resilient material which performs the multiple functions of holding the lip seal element in sealed relation with its associated member, of maintaining an annular edge lip portion of the lip seal element in sealing engagement with the other member and of permitting easy removal and replacement of the lip seal element and O-ring if circumstances warrant.
Another object is to provide a lip seal assembly employing an annular lip seal element of resilient material and an O-ring of resilient material, the O-ring exerting bias pressure on the lip seal element to insure a continuing sealed relationship between the respective parts of the assembly. The O-ring, preferably formed of an elastomer, tends to swell with time in the presence of oil such as commonly is used with seals of this type, the swelling of the O-ring being effective to increase bias pressure, thereby compensating for wear and shape change of the lip seal element.